1ahe: Difference between revisions
New page: left|200px<br /><applet load="1ahe" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ahe, resolution 2.3Å" /> '''ASPARTATE AMINOTRANSF... |
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[[Image:1ahe.gif|left|200px]]<br /><applet load="1ahe" size=" | [[Image:1ahe.gif|left|200px]]<br /><applet load="1ahe" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1ahe, resolution 2.3Å" /> | caption="1ahe, resolution 2.3Å" /> | ||
'''ASPARTATE AMINOTRANSFERASE HEXAMUTANT'''<br /> | '''ASPARTATE AMINOTRANSFERASE HEXAMUTANT'''<br /> | ||
==Overview== | ==Overview== | ||
Mutation of six residues of Escherichia coli aspartate aminotransferase | Mutation of six residues of Escherichia coli aspartate aminotransferase results in substantial acquisition of the transamination properties of tyrosine amino-transferase without loss of aspartate transaminase activity. X-ray crystallographic analysis of key inhibitor complexes of the hexamutant reveals the structural basis for this substrate selectivity. It appears that tyrosine aminotransferase achieves nearly equal affinities for a wide range of amino acids by an unusual conformational switch. An active-site arginine residue either shifts its position to electrostatically interact with charged substrates or moves aside to allow access of aromatic ligands. | ||
==About this Structure== | ==About this Structure== | ||
1AHE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4 and PLP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate_transaminase Aspartate transaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.1 2.6.1.1] Full crystallographic information is available from [http:// | 1AHE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=PLP:'>PLP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate_transaminase Aspartate transaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.1 2.6.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AHE OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Jansonius, J | [[Category: Jansonius, J N.]] | ||
[[Category: Malashkevich, V | [[Category: Malashkevich, V N.]] | ||
[[Category: PLP]] | [[Category: PLP]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
[[Category: transferase (aminotransferase)]] | [[Category: transferase (aminotransferase)]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:44:30 2008'' | ||
Revision as of 09:44, 21 February 2008
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ASPARTATE AMINOTRANSFERASE HEXAMUTANT
Overview
Mutation of six residues of Escherichia coli aspartate aminotransferase results in substantial acquisition of the transamination properties of tyrosine amino-transferase without loss of aspartate transaminase activity. X-ray crystallographic analysis of key inhibitor complexes of the hexamutant reveals the structural basis for this substrate selectivity. It appears that tyrosine aminotransferase achieves nearly equal affinities for a wide range of amino acids by an unusual conformational switch. An active-site arginine residue either shifts its position to electrostatically interact with charged substrates or moves aside to allow access of aromatic ligands.
About this Structure
1AHE is a Single protein structure of sequence from Escherichia coli with SO4 and PLP as ligands. Active as Aspartate transaminase, with EC number 2.6.1.1 Full crystallographic information is available from OCA.
Reference
Alternating arginine-modulated substrate specificity in an engineered tyrosine aminotransferase., Malashkevich VN, Onuffer JJ, Kirsch JF, Jansonius JN, Nat Struct Biol. 1995 Jul;2(7):548-53. PMID:7664122
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